Reduced activity of Mg2+- and Ca2+-dependent adenosine triphosphatase in seminal fluid of patients with oligozoospermia.

Mg2+- and Ca2+-dependent ATPase activity, fructose and divalent cation concentrations were determined in seminal plasmas from men with oligozoospermic ejaculates and from those with normal sperm count. The mean activity of the Mg2+- and Ca2+-stimulated ATPase from the former was 59 nmol . 0.1 ml-1 . This is significantly (p less than 0.005) lower than for men with a normal sperm count (corresponding figure is 87 nmol . 0.1m1-1 . min-1). As regards the concentrations of Mg2+, Ca2+ and Zn2+ in the seminal plasmas from these two groups there was no significant difference. The same was also valid for the fructose concentrations. The Mg2+- and Ca2+-stimulated ATPase activity as well as fructose and divalent cation concentrations were also determined in seminal plasmas from men before and after vasectomy. After vasectomy, only the ejaculates devoid of spermatozoa were included in the comparative studies. No significant difference was observed between the seminal plasmas from men before and after vasectomy. These findings support the view that the Mg2+- and Ca2+-stimulated ATPase system does not derive from the spermatozoa. Possible explanations for the significantly lowered Mg2+- and Ca2+-dependent ATPase activity from patients with oligozoospermia are given.